The invention relates to an attachment for a finisher for laying and compressing road pavements, the finisher having a chassis with a driving aggregate, a material supply container, a driver""s cabin, a distributing device, a transporting device as well as a tamping beam.
The supplementary attachment can be mounted on commercially available finishers and preferably serves for laying two-layer road asphalt pavements. However, it is possible also with said attachment to lay concrete layers or combined concrete and asphalt pavements, as well as road pavements of any type.
It is known in the prior art to lay road pavements on road constructions with the help of finishers. Currently dominating for this purpose is the asphalt road construction method because said construction material offers a number of advantages. In order to adapt the asphalt type of road surfacing in a superior way to the stresses imposed by heavy traffic, it is deemed desirable to increase the degree of compression and to reduce the thickness of the top layers. Compressed asphalt is increasingly used in order to achieve effective sealing of the top layer as well as to minimize the aging of the binding agents and to avoid tracking grooves, surface damages, cracks and chipping. The road paving is laid, for example with two finishers, one running directly after the other.
FR-A 2,697,036 describes a finisher that produces a main pavement which is suitable for a road with motor vehicle traffic, for example, and lays next to it a secondary pavement that is suitable for bicycle traffic, for example. The laying of hot-on-hot is not possible with this finisher over the entire laying width because rolled asphalt is a very viscous mass that can be distributed over the base or transported only by means of screw conveyors or other devices with high expenditure of force.
Furthermore, a finisher is known from EP 0 730 694 B1 that permits laying and compacting a two-layer top asphalt coat with only one fishing machine. A second conveying and distributing system is mounted on said finisher on an enlarged base frame.
A drawback of said arrangement is that for laying two asphalt layers, a special finisher is required that can be employed only for the special task of laying a two-layer asphalt structure, and which, furthermore, requires very high manufacturing costs.
It is the object of the invention to provide a device, in combination with a conventional finisher, which permits the laying of two layers of pavement in an economic manner, even if consisting of different materials, and which can be manufactured at favorable costs. In addition, a simple conversion of the finisher makes it possible to be employed both for laying multi-layered road pavements and for the conventional laying of a pavement comprising only one layer.
The problem is solved according to the invention with the characterizing features of claims 1.
Advantageous further developments of the device as defined by the invention are specified in the dependent claims.
A finisher equipped with the attachment as defined by the invention permits the laying of a two-layer asphalt pavement or also the laying of top coats consisting of other materials with one machine that can be adapted to the given task by only refitting an existing finisher by mounting on such an existing finishing machine, or removing from it, only one attachment. Said attachment can be easily removed again, so that the user requires only one machine that can be employed both for the conventional laying of only one paving layer and for laying a two-layer pavement. Furthermore, the machine can be manufactured at substantially more favorable cost than a separate double-finisher.
A finisher equipped with the attachment as defined by the invention has two separate tamping beams, whereby the first tamping beam is designed as a standard or highly compressing beam, and the second tamping beam can be designed both as a standard tamping beam and a highly compressing beam. The first tamping beam serves as the laying and pre-compressing beam and permits extremely high pre-compression, for which reason a substantially higher flatness of the two-layer pavement is achieved as compared to pavements laid according to known methods. The planeness so achieved, in conjunction with high pre-compression, makes it possible to reduce after-compression, which may still be required, to a minimum.
An important advantage of the attachment as defined by the invention lies in that series-produced components usable for finishers of the usual type can be used for the components xe2x80x9cpre-distributing systemxe2x80x9d and xe2x80x9ccompression beamxe2x80x9d of the attachment.
Owing to the arrangement of two tamping beams as defined by the invention it is possible, furthermore, to produce separate profiles for the two layers. It is possible, for example, to incorporate rain water gutters. Another important advantage is that a finisher of the conventional is obtained in a simple way by simply removing the attachment, whose functions remain fully preserved and which can operate without an additional transfer device.
It is possible to provide the control of the layer thickness, the so-called leveling coupled with the first beam, or independently thereof with a separately operating control for the second beam. Commercially available rigid beams or also extendable beams can be employed as laying beams.